Web drying apparatus



Nov. 4, 1952 H. K. STEINFELD WEB DRYING APPARATUS Filed Feb. '7, 1951 JNVNTOR. HANS K. STE/NFELD Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE WEB DRYING APPARATUS Hans K. Steinfeld, Swarthmore, Pa., asslgnorto American Viscose Corporation, Wilmington, Del., a corporation of Delaware Application Februaryl, 1951 SerialNo. *209,821

(Cl. 32k-i114) 1'4 Claims.

The ,present invention relates to an apparatus for drying webs, such as those formed of regenerated cellulose and the like. More particularly, the invention relates toy an improved sectionalized drying hood to .be used in conjunction with -conventional drying rolls 'now presently lemployed in drying regenerated cellulose 'and the like. Web., as used throughout'the specification and claims 'is in'tended vto include all types of Isheet materials, such as textile fabric, paper, films formed lfrom regenerated cellulose, cellulose ethers and esters, various plastic materials, such as polyethylene, Saran, polyvinyl chloride, and the like. V For purposes .of vsimplicity the invention will be' described as itis applicable to the treatmenty of Va web or Vlm of regenerated cellulose or cellophane, it 'being understood, of course, that this is not intended in a limitative sense.

It is the generally accepted practice for commercial operation to dry a web of regenerated cellulose by passing it around internally heated rolls or drums. The continuously produced web is passed around a series of such rolls or 'cylinders, which are arranged in two tiers so that the film or web rst comes `in contact with or is supported on one side by Aa Yroll `in the upper tier and then on the other side by a roll in the lower tier, and soon, alternately throughout the length -of the train of rolls. The axes of the rolls of the lower tier 4lie between the axes of the rolls vof the upper tierra-nd -all -of 'the rolls are rotated at the same peripheral speed.

Even though such a system is now in general use there are a number of disadvantages :attendant thereto. When regenerated cellulose Vfilm lea-ves the last `treating bath and enters the dryf ing section of the machine, ,iit contains .approximately 30.0 to 400% moisture, vvwhich moisture content is usually reduced to 5 to .10% during drying. Therefore, :a very substantial volume change 'takes place during the water removal, which manifests itself in shrinkage, i. e., loss of area and thickness, The shrinkage must be uniform throughout the -web .in order to produce a uniform- ,product 'and for .production purposes there is always the desire to reduce the shrinkage to :a minimum. f f

To insure even drying of vthe web, and conse quently evenshrinkage thereof, it is presently the practice to Ablowair, which ,may be cold or heated, over the film or web While passing over the 'heated drying rolls. This is done to .remove the moisture-laden air from contact with the web and to assist in the drying thereof. It is necessary to remove the ymoisture-laden air from intimate 2 contact with the Lweb inorder to- :avoid an undesirable-equilibrium from being set up between the amount of water in the web and inthe air immediately adjacent thereto, which obviously would hinder the attainment of the desired moisture content in the finished product.

This practice of blowing -air over the web on the drying rolls has not proven too satisfactory because the `supplied r'air diffuses "in :an uncontrolled manner over wide areas of the film or web and particularly in a direction vparallel to the axes -olf 'the drying rolls which rcauses uneven drying of the nlm `and `results in a product of inferior quality. The unevendrying is caused by the edges of .the web drying at va faster rate than the center of the web vbecause the supply air hits the edge of the web on -looth sides thereof. The reason for this is -attributed to vthe fact that the contaminated, moisture-'laden air is `not exhausted immediately at 'the source of contamination but is permitted to circulate'and recirculate lfreely over the lm surface until it is picked up by the general exhaust system.

It is a general object of the present invention to provide an apparatus or drying system which will overcome the above-mentioned difficulties and disadvantages.

VIt is another lob-ject of the `invention to provide an apparatus which will supply air to each integral part of the web at the same rate and immediately remove or exhaust the contaminated, moisture-laden air at the source of contamination.

Another -obect of vthe invention lis to prov-ide an air supply and exhaust system -for each individual vdryer roll confined within as limited a space as practical and operational limits will permit Vand in addition still maintainthe ladvantages of -a full-y `open Adryer construction for ready access to the equipment in the event of `breaks in the web and for maintenance.

`Other objects and advantages of the present invention 'will be apparent from the description thereof '-hereinafter,

For a better understanding of the following description of the invention reference should be had to the accompanying drawing which illustrates preferred embodiments thereof, the same not being intended in a limitative sense, and in which- Figure l is a front elevation view showing a drying rou and an airsupply :and exhaust system mounted in conjunction therewith,

Figure 2 is a side elevation view of a section of. the drying vend of .a machine,

Figure 3 is a bottom view oi' the air supply and exhaust system shown in Figure 1,

Figure 4 is a sectional view taken along the line A-A of Figure l,

Figure is a sectional view taken along the line B--B of Figure l, and

Figure 6 is a viewgtaken along line C`C of Figure 1.

In general, the objects of the present invention are accomplished by placing above each roll in the upper tier of the train a series of nozzles or small ducts, the series extending parallel to the axis of the roll, which direct air against the web being carried over the roll. Means for removing the moisture-laden air are placed adjacent each set of nozzles above each roll in the upper tier. The nozzles and means for removing the moisture-laden air are positioned in close proximity to the roll surface andgare disposed along the entire length of the roll. If desired, the same system may be employed in conjunction with each of the rolls at the lower tier of the train, but only the upper rolls need be supplied with air supply and removal means to accomplish the objects of the present invention.

Referring to Figures 1 and 2 of the drawing,

the web drying mechanism comprises two tiers of the drying rolls 2 and 3 all of which are rotatably mounted and positively driven at the same peripheral speed such as by gears, belt, chain and sprocket, etc. Each roll is heated internally by any suitable means (not shown), for example steam, hot water, electric coils, etc. Positioned above each of the rolls 3 in the upper tier is a hood 4 extending longitudinally of the rolls or parallel to the axes thereof. The center line of the hood is preferably offset slightly from a vertical plane through the center line of the roll above which it is positioned and oiset in the trailing direction. If desired, the center line of the hood may be in line or coincide with the center line of the roll above which it is positioned. The hoods 4 are supported above the rolls 3 by the rods or pipes 5 and 6 which extend the length of the roll train, transversely to the rolls and parallel to the direction of travel of the web. lIhe hoods are fastened to the rods as follows: fastened to hood 4 is a yoke-shaped bracket 1 which in turn is fastened to the rod 5 by the U- bolts or hangers 8 and 9 (see Figure 2). Also fastened to each side of the hood 4 are the L- shaped brackets or angle irons ID and I I and each of these are in turn fastened to the rod 6 by the U-bolts or hangers I2 and I3 (see Figure 5).V

The hoods 4 are divided into two sections or chambers, the air-supply chamber I4 and the exhaust chamber I5. In the upper face of hood 4 near one end thereof there is an opening I5 leading to the air-supply chamber. I4 (see Figure 3). Into opening I3 there is inserted the conduit section I7. Another opening I8 in the top of hood opens into the exhaust chamber I5 (see Figure 3), and the conduit section I9 is inserted in the opening I8. -The section I'I is connected to a conduit 23 bymeans of a clamp 'collar 2I, the conduit 2t being in turn connected to the main air duct 22. The air is heated by any suitable means (not shown) while in duct 22 or before entering the same. If desired, the air may be humidied in addition to being heated. Section I9 is connected to a conduit 23 by means of a clamp collar 24, the conduit 23 being in turn connected to a vacuum duct 25.

The air supply chamber I4 is separated from the exhaust chamber I5 by an L-shaped partition 4 26 (see Figure 5) which extends practically the entire length of the hood 4, being fastened to the end of the hood away from the air supply entrance and at the other end to a curved partition 2'I. Referring to Figure 6, the L-shaped partition is supported by the bracket 28 and is also connected to a partition l2%) (see Figure `4) which blocks oii the air supply chamber from the lower part of the exhaust chamber formed by the L- shaped partition.

Referring to Figures 1 and 5, the bottom of the Vair-supply chamber I4 is formed by an L-shaped member 30 which is welded to the partition 26 at one end. The part 33a of the L-shaped member extends upwardy to form an opening between the wall 4a of hood 4 and the member 30. This opening is divided vup into a number of small ducts or nozzles SI by means of the separating members or partitions 32; The air passes through these nozzles 3I through an elongated opening 33, and down against the web 34 passing over roll 3. The elongated opening 33 is formed by the wall 4a of hood 4 and the angle irons or plates 35 which are adjustably mounted on the L- shaped member 30 by means of bolts 35 which pass through the partitions 35 and the slots 3'I in member 33. A plain washer 35, spring washer 39 and nut 43 are placed on each of the bolts 36. As shown in Figure 3 there are three angle partitions 35 employed in the embodiment shown but only one or two or more than three such partitions may be employed if desired.

A lnumber of thumb screws 4I 33 can be easily regulated. When employing a number of adjustable angle partitions 35 the amount of air coming into contact with any part of the web is easily regulated. In this way, even,v drying across the web is assured even though oneA portion of the web may contain more moisture than another portion. p V'Referring to Figure 4, the L-shaped partition 26 is supported along its length by the` brackets 43, fastened between the partition and the wall 46 of hood 4.

An elongated opening 44 is formed by the L- shaped partition 25 and the wall 46 of hood 4 through which the contaminated, moisture-laden air is drawn into chamber I5.

VReferring to Figure 2, the arrows show the direction of ow of the heated air through chambervl, through the nozzles 3| and opening 33 againstthe web 34 on the rolls. The air picks up the moisture from the web and then enters the opening 44 to the exhaust chamber I5 of Vthe' same hood from which it emerged or of the hoodover an adjacent roll. The heated roll `drives the moisture through the web and the air picks it up and directs it to the exhaust system. Hence, the film or web is dried on both sides at once. The flow of air may be regulated depending upon the amount of moisture that has to be removed from the web. The moisture content of the finished web* may also be regulated by the apparatus of the present invention in that the air coming into contact with the Web toward the end of the train may be humidied to the extent necessary.

are passed` through the hood wall 4a and the downwardly-V extending portions 35a of the angle partitions 35.

In 'this way 'thedesired equilibrium between the moisture in the air and web can be reached.

It is to be noted that the hood 4 is tapered in order to provide for substantially uniform distribution of -air over the entire web surface. The hoods 4 should be pla-ced `as close to the surface of rolls 3 `-as is possible under normaloperating conditions. Y

The p resent invention provides a means lof transporting drying air to and from the web area under conditions more controllable than under present practice using -known equipment. HWebs of any thickness maybe dried in the apparatus herein described with slight adjustments in temperature and flow of air where necessary.

The present invention enables one'todry a continuously moving web evenly vthroughout the same without danger of undue shrinkage, puckering, etc. ofthe web. The apparatus is easy -to construct and install on -roll drying machines and is 'easily controlled. The present invention increases production since the web materialca-n be dried at a higher rate of Speed. Numerous other advantages of the invention will be evident to those skilled in the art. v

It should be understood thatthe `invention is not limited to the embodiments described and illustrated 4by way of example and that various structural changes and modifications may be made without departing from the spirit andscope of the invention as defined in the appended claims.

I claim:

l. A drying apparatus Afor drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in cross-section as it extends the length Yof the roll, an exhaust chamber in the housing extending the length of the roll for receiving the saturated medium, a partition extending the length of the housing to separate the exhaust chamber from the supply chamber, the inlet to the supply chamber being positioned at the end of the housing having the largerA cross-section, `the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll'and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extendinglthe length of the roll along the housing wall opposite the rst mentioned wall.

2. A drying apparatus for drying a travelling web comprising a roll, a housingadjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in cross-section as it extends the length of the roll, .an exhaust chamber in the housing extending the length of the roll for receiving the saturated medium, a partition extending the length of the housing to separate the exhaust chamber from the supply chamber, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending -the length of vthe roll .along .one wall of the housing, the iexhaust. chamber v)having an elongated entrance opening 'positioned directly over vthe roll and vextending 'the lengthpzof :the roll along 4the housing wall opposite they first chamber 'having a gradual decrease in :cross-'section as it extends the length 'of the roll, :an :exhaust chamber in the housing extending fthe length of the roll for receiving the 'saturated medium, a partition extending the length of the housing to separate the exhaust chamber from the supply'chamber, the inlet'to vthe supply cham*- ber being positioned at the end lof lthe v'housing having the larger cross-section, the A'outlet fof the exhaust chamber vbeing `positioned at ther end of the housing having the larger -cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of vthe roll along one wall of the housing, the exhaust chamber having an elongated entrance openingpositioned directly over the roll and extending zthe length ofthe roll along the housing wall opposite Athe first rmentioned wall, separating members dividing the discharge opening-into a number of small ducts, spaced members -in the :elongated entrance opening to connect the 'housing wall with the partition member, said spaced members lending reinforcement to the partition member with relation tothe housing.

4. A drying apparatus for drying a travelling web comprising a roll, va housing adjacent the roll comprising a drying medium-supply chamber extending lengthwise of Athe roll, said supply chamber having a gradualdecrease in .cross-sew tion as it extends the length of the roll, an v-exhaust chamber in the housing yextending thelength of the roll for receiiving the saturated medium, a partition extending the length of the housing to separate the exhaust chamber from the supply chamber, the inlet to the supply chamber being positioned at 'the end of the "housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, `the supply chamber having an elongated .discharge opening positioned directly over the roll and extending the length .of the roll along one wall `of the housing', the exhaust chamber having. an elongated .entrance opening r.positioned directly over the roll and extending the length of the roll along the housing wall opposite the first `mentioned wall, an elongated nozzle outside. of the discharge opening for directing the 'air from `the discharge opening to the roll comprising van extension of the housing wall adjacent the dis. charge opening and a Aplate .Opposite `thehous'ing wall extension, said plate facing the wall'exten-` Sion.

l5. A drying apparatus for .drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium vsupply chamber extending lengthwise of the roll, said'supply cham' ber having a gradual decrease in cross-section as it extends the length of the roll, an exhaust chamber in the housing extending lthe length or the roll for receiving the saturated medium, a partition extending the length Aof the housing to separate Vthe exhaust chamber 'from the supply chamber, .the inlet to the supply chamber being ps'itioned at the end of the housing having the larger Ycross-section, the outlet of the exhaust chamber being positioned at the end of the housingrhaving the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the rst mentioned wall, an elongated adjustable nozzle outside of the discharge opening for directing the air from the discharge opening to the roll comprising an ex tension of the housing wall adjacent the elongated discharge opening, a sliding plate opposite the housing wall extension, said plate facing the wall extension and means for changing the position of the sliding plate with relation to the wall extension to x the area between the plate and the housing wall.

6. A drying apparatus for drying a travelling web comprising Ya roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a, gradual decrease in crosssection as it extends the length of the roll, an exhaust chamber in the housing extending the length of the roll for receiving the saturated medium, a partition extending the length of the housing to separate the exhaust chamber from the supply chamber, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge openingV positioned directly over the roll and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the first mentioned wall, an elongated nozzle outside of the discharge opening for directing the air from the discharge opening to the roll, said nozzle being closer to the roll than the entrance opening of the exhaust chamber.

7. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a back wall, a front wall adjacent the roll, two side walls, said side walls extending beyond the front wall, a drying medium supply chamber in the housing having a gradual decrease in cross-section as it extends the length of the roll, an exhaust chamber in the housing extending the length of the roll for receiving the saturated medium, a partition extending the length of the housing to separate the exhaust chamber from the supply chamber, the inlet to the supply chamber being positioned at the end of the housing having` the larger cross section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross-section, the supply chamber having an elongated discharge opening positioned directly over the roll and extendingY the length of the roll along onewall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the rst mentioned wall, an adjustable nozzle outside of the discharge opening comprising the extension of the housing wall adlent the/discharge opening, a sliding plate facing the wall extension, said plate being atd` tachedto the front wall, thumb screws for connecting the plate with the wall extension to change the position of the sliding plate with relation to the wall extension and x the area between the plate and the wall extension.

8. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in crosssection as it extends the length of the roll, an exhaust chamber in the housing extending along the length of the roll positioned above the supply chamber, an L-shaped partition extending the length of the housing to separate the exhaust chamber from the supply chamber, one leg of the L-shaped member extending inwardly from one housing wall and extending partially across the cross-section of the housing, the second leg of the member extending downwardly at a angle from the first extended leg in a position parallel with the housing wall, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the first mentioned wall.

9. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in crosssection as it extends the length of the roll, an exhaust cham-ber in the housing extending along the length of the roll positioned above the supply chamber, an L-shaped partition extending the length of the housing to separate the exhaust chamber from the supply chamber, one leg of the L-shaped member extending inwardly from one housing wall and extending partially across the cross-section of the housing, the second leg of the member extending downwardly at a 90 angle from the rst extended leg in a position parallel with the housing wall, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section. the outlet of the exhaust `chamber being positioned at the end of the housing having a larger crosssection, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of the roll along one wall of the housing, the exhaust chamber having an entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the rst mentioned wall, the entrance opening being formed by the housing wall, the second leg of the L-shaped member and the ends of the housing.

10. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in crosssection as. it extends the length of the roll, an exhaust chamber in the housing extending along the lengthlof .the roll positioned above the supply 9 chamber, an rL -shaped partition extending' the length ofVv the housing to separate the exhaust chamberl fromthe supply chamber, one leg of theL-shaped member extending inwardly from one housing wall and extending partially across rolll and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over 'the roll'and extending the length o f the roll along the housing wall opposite the rst mentioned wall, the discharge opening being separated from the entrance opening by a leg of a second L-shaped member extending the length of the roll, said leg extending inwardly toward the housing wall adjacent the discharge opening from the free end and at a 90 angle to the free end of the downwardly extending leg of the rst L.-shaped member.

ll. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in crosssection as it extends the length of the roll, an exhaust chamber in the housing extending along the length of the roll positioned above the supply chamber, an L-shaped partition extending the length of the housing to separate the exhaust chamber from the supply chamber, one leg of the L-shaped member extending inwardly from one housing wall and extending partially across the cross-section of the housing, the second leg of the member extending downwardly at a 90 angle from the iirst extended leg in a position parallel with the housing wall, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the rst mentioned wall, the discharge opening being separated from the entrance opening by a leg of a second L-shaped member extending the length of the roll, said leg extending inwardly toward the housing wall adjacent the discharge opening from the free end and at a 90 angle to the free end of the downwardly extending leg of the first L-shaped member, the discharge opening being formed by the housing wall, the ends of the housing, and the remaining leg of the second L-shaped member disposed vertically to the first leg of the second L-shaped member toward the roof of the housing.

12. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in cross-section as it extends the length of the roll, an exhaust chamber in the housing extending along the length of the roll positioned above the supply chamber, an L-'shaped partition extending the length of the housing to separate the exhaust chamber from the supply chamber, one leg of the L-shaped member extending inwardly from one housing wall and extending partially across the cross-section of the housing, the second leg of the member extending downwardly at a angle from the first extended leg in a position parallel with the housing wall, the inlet to the supply chamber being positioned at the end` of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross-section, the supply chamber having an elongated discharge opening positioned directly over the roll' and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall, opposite the iirst mentioned wall, a nozzle positioned at the discharge opening of the supply chamber.

13. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in cross-section as it extends the length of the roll, lan exhaust chamber in the housing extending along the length of the roll positioned above the supply chamber, an L-shaped partition extending the length of the housing to separate the exhaust chamber from the supply chamber, one leg of the L-shaped member extending inwardly from one housing Wall and extending partially across the cross-section of the housing, the second leg of the member extending downwardly at a 90 angle from. the rst extended leg in a position parallel with the housing wall, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of the roll along one wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the first mentioned wall, the discharge opening being separated from the entrance opening by a leg of a second L-shaped member extending the length of the roll, said leg extending inwardly toward the housing wall adjacent the discharge opening from the free end and at a 90 angle to the free end of the downwardly extending leg of the first L-shaped member, a series of angle irons attached to the leg of the second I -shaped member, a nozzle for the discharge opening being formed by the downwardly extended legs of the angle irons and the housing wall adjacent the discharge opening.

14. A drying apparatus for drying a travelling web comprising a roll, a housing adjacent the roll comprising a drying medium supply chamber extending lengthwise of the roll, said supply chamber having a gradual decrease in crosssection as it extends the length of the roll, an exhaust chamber in the housing extending along the length of the roll positioned above the supply chamber, an L-shaped partition extending the length of the housing to separate the exhaust chamber from the supply chamber, one leg of the L-shaped member extending inwardly Vfrom one housing wall and extending partially across the cross-section of the housing, the second leg of the member extending downwardly at a 90 angle from the rst extended leg in a position parallel with the housing wall, the inlet to the supply chamber being positioned at the end of the housing having the larger cross-section, the outlet of the exhaust chamber being positioned at the end of the housing having the larger cross section, the supply chamber having an elongated discharge opening positioned directly over the roll and extending the length of the roll along one Wall of the housing, the exhaust chamber having an elongated entrance opening positioned directly over the roll and extending the length of the roll along the housing wall opposite the first mentioned wall, the discharge opening being separated from the entrance opening by a leg of a second L-shaped member extending the length of the roll, said leg extending inwardly toward the housing wall radjacent the discharge opening from the free end and at a 90 angle to the free Yend of the downwardly extending leg of the rst L-shaped member, a series of angle irons attached to the leg of the second L-shaped member, a nozzle for the discharge opening being formed by the downwardly extended legs of the angle irons and the housing wall adjacent the discharge opening, elongated slots in one of the legs of the angle irons, a series of bolts through the slots to secure the angle irons to the second L-shaped member, a series of thumb screws passing through the housing wall and the downwardly extended legs of the angle irons toregulate the size of the opening of the nozzle by sliding the angle irons along the elongated slots in a direction toward or away from the housing wall when the angle iron attaching bolt is loosened.

HANS K.' STEINFELD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,470,953 Bassler Oct. 16, 1923 1,933,960 Brabaek Nov. 7, 1933 2,159,248 Brabak May 23, 1939 2,218,282 Downs Oct. 15, 1940 2,225,505 Offen Dec. 17, 1940 2,268,988 Hess et a1. Jan. 6, 1942 2,304,818 Grupe Dec. 15, 1942 

